Continuity mistake: When Alex and his droogs come in on Billy Boy making ready to rape the young girl, the first shot shows the lacing of a shoe or sandal on the girl's left calf, but afterward it jumps to her right.

Continuity mistake: When Alex goes out from the cat woman's house, his pants are white and clean; then Dim crash a bottle onto his face and before falling down Alex's pants are dirty at knees. In the following scene, at the interrogation, his pants are clean again.

Continuity mistake: When Alex is seeing the prison governor about being released, the governor's glasses are on a pile of papers on his desk. From various camera angles they are on some files, back on the papers or halfway between.

Continuity mistake: Look at the scene where Alex beats Georgie and Dim and they fall in the river. Alex politely offers his hand to Dim, and in the background you can see Georgie with no hat. Shortly afterwards, he's got his hat on.

Continuity mistake: The main character's name is several times in the film mentioned as 'Alexander DeLarge', but in the newspaper articles detailing his release from prison, they call him 'Alex Burgess'. Burgess is the surname of the author of the book the film is based on, so they might have originally intended to name him so as an homage.

Continuity mistake: When the governor is talking to Alex about having the procedure done, the governor says "Tomorrow you will go..." and the position of his hands changes quicker than he could have moved them.

Continuity mistake: When Alex is eating spaghetti with the writer and the two reporter types at the end, Alex has a napkin on the table. When the shot changes at the end of the scene the napkin is gone.

Continuity mistake: When Alex is welcomed to jail, he has to remove his clothes, which are put in a box by a guard. The guard's right hand changes positions with the camera angles. Sometimes his hand is lying on the box, sometimes on the box cover beside it.

Continuity mistake: When the cops have Alex in the holding cell and he is bleeding, a cop throws a pile of napkins at him and one of them lands on his leg. In the next shot, the napkin has disappeared.

Continuity mistake: At the beginning when Alex and his boys go to the old theatre you can see Billy Boy, who is preparing to rape a girl, then loses his hat and the very next moment he has it on, as if nothing has happened.

Continuity mistake: When Alex, the writer, and the other two political people are sitting at the table near the end of the movie, not only does the amount of sauce change on the spaghetti, but the amount of spaghetti changes from shot to shot even after Alex has stopped munching on it. This isn't part of the director's ploy.

Continuity mistake: The water in the marina alternates from being wavy when Alex and his droogs are silently walking towards the camera, to completely still a moment later when George is sent tumbling into it.

Continuity mistake: When Alex goes home in the night, he turns on his cassette player, takes out a cassette from the player, then after a few seconds a closeup is shown of the slot with a cassette inside that he removes again.

Continuity mistake: When Frank first pours the wine for Alex he fills it all the way to the top. The shot changes and he is still pouring the wine however the level of the glass has dropped to half full and he fills it up again.

According to actor Malcolm McDowell, director Stanley Kubrick was concerned that the Droog attack on F. Alexander and his wife would become just another dark, cruel and violent scene in a movie that was already full of dark, cruel and violent scenes. Kubrick wanted the Alexander home invasion to stand out as genuinely horrifying, but he was at a creative impasse. After Kubrick shut down production for several days to ponder the problem, he thought of Alex dancing during the attack. Malcolm McDowell suggested dancing (and singing) along to "Singin' in the Rain," as it was the only song to which he knew all the words.